TY - JOUR
T1 - Green additive to upgrade biochar from spent coffee grounds by torrefaction for pollution mitigation
AU - Lee, Kuan Ting
AU - Du, Jyun Ting
AU - Chen, Wei Hsin
AU - Ubando, Aristotle T.
AU - Lee, Keat Teong
N1 - Funding Information:
The authors acknowledge the financial support of the Ministry of Science and Technology, Taiwan , R.O.C., under contracts MOST 106-2923-E-006-002-MY3 , MOST 109-2221-E-006-040-MY3 , and MOST 109-3116-F-006-016-CC1 for this research. This research was also supported in part by Higher Education Sprout Project, Ministry of Education to the Headquarters of University Advancement at National Chen Kung University (NCKU) . The authors gratefully acknowledge the use of EM003600 and XRD005100 of MOST 110-2731-M-006-001 belonging to the Core Facility Center of National Cheng Kung University .
Funding Information:
The authors acknowledge the financial support of the Ministry of Science and Technology, Taiwan, R.O.C. under contracts MOST 106-2923-E-006-002-MY3, MOST 109-2221-E-006-040-MY3, and MOST 109-3116-F-006-016-CC1 for this research. This research was also supported in part by Higher Education Sprout Project, Ministry of Education to the Headquarters of University Advancement at National Chen Kung University (NCKU). The authors gratefully acknowledge the use of EM003600 and XRD005100 of MOST 110-2731-M-006-001 belonging to the Core Facility Center of National Cheng Kung University.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/9/15
Y1 - 2021/9/15
N2 - A green approach using hydrogen peroxide (H2O2) to intensify the fuel properties of spent coffee grounds (SCGs) through torrefaction is developed in this study to minimize environmental pollution. Meanwhile, a neural network (NN) is used to minimize bulk density at different combinations of operating conditions to show the accurate and reliable model of NN (R2 = 0.9994). The biochar produced from SCGs torrefied at temperatures of 200–300 °C, duration of 30–60 min, and H2O2 concentrations of 0–100 wt% is examined. The results reveal that the higher heating value (HHV) of biochar increases with rising temperature, duration, or H2O2 concentration, whereas the bulk density has an opposite trend. The HHV, ignition temperature, and bulk density of biochar from torrefaction at 230 °C for 30 min with a 100 wt% H2O2 solution (230-100%-TSCG) are 27.00 MJ∙kg−1, 292 °C, and 120 kg∙m−3, respectively. This HHV accounts for a 29% improvement compared to that of untorrefied SCG. The contact angle (126°), water activity (0.51 aw), and moisture content (7.69%) of the optimized biochar indicate that it has higher resistance against biodegradation, and thereby can be stored longer. Overall, H2O2 is a green treatment additive for SCGs solid fuel. This study has successfully produced biochar with greater HHV and low bulk density at low temperatures. The green additive development can effectively reduce environmental pollutants and upgrade wastes into resources, and achieve “3E”, namely, environmental (non-polluting green additives), energy (biofuel), and circular economy (waste upgrade). In addition, the produced biochar has great potential in the fields of bioadsorbents and soil amendments.
AB - A green approach using hydrogen peroxide (H2O2) to intensify the fuel properties of spent coffee grounds (SCGs) through torrefaction is developed in this study to minimize environmental pollution. Meanwhile, a neural network (NN) is used to minimize bulk density at different combinations of operating conditions to show the accurate and reliable model of NN (R2 = 0.9994). The biochar produced from SCGs torrefied at temperatures of 200–300 °C, duration of 30–60 min, and H2O2 concentrations of 0–100 wt% is examined. The results reveal that the higher heating value (HHV) of biochar increases with rising temperature, duration, or H2O2 concentration, whereas the bulk density has an opposite trend. The HHV, ignition temperature, and bulk density of biochar from torrefaction at 230 °C for 30 min with a 100 wt% H2O2 solution (230-100%-TSCG) are 27.00 MJ∙kg−1, 292 °C, and 120 kg∙m−3, respectively. This HHV accounts for a 29% improvement compared to that of untorrefied SCG. The contact angle (126°), water activity (0.51 aw), and moisture content (7.69%) of the optimized biochar indicate that it has higher resistance against biodegradation, and thereby can be stored longer. Overall, H2O2 is a green treatment additive for SCGs solid fuel. This study has successfully produced biochar with greater HHV and low bulk density at low temperatures. The green additive development can effectively reduce environmental pollutants and upgrade wastes into resources, and achieve “3E”, namely, environmental (non-polluting green additives), energy (biofuel), and circular economy (waste upgrade). In addition, the produced biochar has great potential in the fields of bioadsorbents and soil amendments.
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U2 - 10.1016/j.envpol.2021.117244
DO - 10.1016/j.envpol.2021.117244
M3 - Article
C2 - 33965857
AN - SCOPUS:85105270044
SN - 0269-7491
VL - 285
JO - Environmental Pollution
JF - Environmental Pollution
M1 - 117244
ER -